To move a window from one workspace to another you have two options:
fix the window, change the workspace and unfix it.
drag the window out of the left/right edge of your screen to move it
one workspace down/up.
You can also use the mouse wheel to switch workspaces up and down if
the pointer is not over a window.

The default colors for the one pixel border in BadWM are:
"goldenrod" for the foreground window,
"gray50" for background windows,
"blue" for fixed windows.
You can change them in the ~/.BadWMrc file.
You will need to restart BadWM then.
For all other settings in the config file you can reload the config
(left <ALT> key + r) to make them effective.